People have used various means for limiting interruptions due to the telephone. In the past, people used switchboards and secretaries to screen incoming, or inbound, calls. Voice mail systems took over some of this role both in the home and in the central office. Today, there are web-based companies managing 3rd-party call control, via the toll-switch network, which allow users to enter call control information through a web portal. There are also edge devices in each of the public telephone company's central offices which provide local control, but offer an extremely limited number of features and do not provide true 3rd-party call control.
The web-based toll systems provide good user interaction but they are not economical and cannot take advantage of local number portability because they do not provide local control and connectivity.
The Public Switched Telephone Network (PSTN) consists of a plurality of edge switches connected to telephones on one side and to a network of tandem switches on the other. The tandem switch network allows connectivity between all of the edge switches, and a signalling system is used by the PSTN to allow calling and to transmit both calling and called party identity.
Until now, optional features were provided by the local service telephone company (telco) through the edge switch at the central office (CO). It was not possible to provide optional features through any other means. Control of these features was done through the first party (calling party) or the second party (called party), or worse yet, manually by calling the business office.
In the past, numerous devices have been built that allow the connection of two lines together at an edge switch. These devices can be used to add features to a telephone network by receiving a call on one line and then dialing out on another line. The problem with these devices is that, because they are connected through an edge switch, transmission losses and impairments occur, degrading the overall connection. In addition, signalling limitations prevent full control, by the subscriber or the system, over the call.
A preferred embodiment of the inventive system described herein connects at the tandem, thereby eliminating these problems.
In the edge devices residing in the PSTN central offices, the 1st party (the calling party) has numerous features available (dialing options). The 2nd party (called party) also has options available such as call forwarding, but these features typically require access from the first or second party's device and are extremely awkward to program. The user interaction is not only awkward, it is limited and requires interaction with the telephone company to provision them. In other words, past systems for provisioning, meaning addition, modification, or control of telephone features, required a subscriber to make the feature selection through the telephone business office. Central office workers would then implement the provisioning under request of the business office.
Call Forwarding is one popular provision. There is signification transmission degradation for Call Forwarding to take place. The calling party pays for a call to the edge device, and the edge subscriber, the called party, pays for the call to the forwarding number. For enhanced inbound call control to occur, a direct 3rd-party call control means is needed.
A variety of services have arisen to address the problems mentioned above. Many of these systems allow the called party to make changes to his/her call forwarding attributes which do not allow direct 3rd-party call control. These services provide good user interaction, some via the internet, but they rely upon the toll network through the use of “800” numbers. This requires the subscriber to pay by the minute and does not allow the subscriber to take advantage of number portability in order to obtain 3rd-party call control. There are other toll network mechanisms for remote call forwarding. For example, MCI offers a service where the customer can remotely change the forwarding target number for “800” numbers. Contacting the ultimate end-user before terminating the first incoming call is similar to the manner in which “800” credit calls and collect calls are processed, but these are not done at the local subscriber level.
In addition to these toll services, there are edge devices that perform some of the same services. Edge devices such as phones and PBXs that include voice mail, inter-active voice response, call forwarding, speed calling, etc., have been used to provide additional call control. These devices allow the phone user direct control over incoming and outgoing calls. The disadvantage of edge devices is that they add cost, degrade voice and transmission quality, can be difficult to program, are not easily programmed remotely, can require the user to pay for two lines, provide lower quality of service, and cannot provide the same level of functionality as a system that controls the PSTN directly. There are Voice Over Internet Protocol (VoiP) products emerging that provide better user interfaces and control but they do not take advantage and voice quality of the PSTN.